Short answer: No, it's not to controversial a subject. Plenty of other cons have LGBT based panels, I've been to them. It's a non-isue, controversy wise.
Having said that, the panels I've been to with a LGBT subject were actually hosted by writers working with LGBT themes. Considering that Fanime has one of THE most immature fan groups I've ever met(Don't get mad, it's just my opinion), I can see anything but a well-structured panel going all downhill, REALLY fast.
Having said that, the panels I've been to with a LGBT subject were actually hosted by writers working with LGBT themes. Considering that Fanime has one of THE most immature fan groups I've ever met(Don't get mad, it's just my opinion), I can see anything but a well-structured panel going all downhill, REALLY fast.